Proposing a kinetic model

We will focus our attention to the Bodenstein reaction, a historically important reaction due to the fact that for the first time a nonelementary kinetic mechanism was postulated (Laidler, 1987)  

For the fast steps, we can invoke pseudoequilibrium such that 

The rate of the reaction is determined from the slow step as 

It is clear that the rate is not proportional to fc[H2][l2] due to the nonelementary kinetics. 

Exercise By choosing different steps as slow or fast, derive alternative rate expressions. 

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Recently Dumas and Hsu (1,8-9) have proposed a kinetic model derived on the assumption of a multiplicity of sites which has a much simpler form than those given by previous workers (6-7). 

Asymmetric autocatalysis has the following intrinsic merits (1) the efficiency is high because the process is automultiplication (2) in an ideal asymmetric autocatalysis, no decrease in the amount of catalyst and no deterioration of the catalytic activity should be observed because the amount of catalyst increases during the reaction and (3) there is no need to separate the catalyst from the product because their structures are identical. Frank proposed a kinetic model of asymmetric autocatalysis without mentioning a specific compound or reaction." ... 

Glaze et al. (1995) proposed a kinetic model for the UV/H202 oxidation using radical and the direct photolysis of the organic compounds. The model utilized the literature values of the rate constants for radical formation and substrate oxidation. It was applied to interpret the data from the oxidation of l,2-dibromo-3-chloropropane (1,2-DBCP) at low levels (less than 500 pg/ L) in simulated and actual groundwater. 

On the other hand, Nomura and Harada [14] proposed a kinetic model for the emulsion polymerization of styrene (St), where they used Eq. 7 to predict the rate of radical entry into both polymer particles and monomer-swollen micelles. In their kinetic model, the ratio of the mass-transfer coefficient for radical entry into a polymer particle kep to that into a micelle kem> K lk,... 

Unzueta et al. [18] derived a kinetic model for the emulsion copolymerization of methyl methacrylate (MMA) and butyl acrylate (BA) employing both the micellar and homogeneous nucleation mechanisms and introducing the radical absorption efficiency factor for micelles, F, and that for particles, Fp. They compared experimental results with model predictions, where they employed the values of Fp=10 and Fn,=10", respectively, as adjustable parameters. However, they did not explain the reason why the value of Fp, is an order of magnitude smaller than the value of Fp. Sayer et al. [19] proposed a kinetic model for continuous vinyl acetate (VAc) emulsion polymerization in a pulsed... 

Based on the ADC model, we proposed a kinetic model for defect formation in II-VI compounds. A system of rate equations describing the interaction between a II-VI crystal and chalcogen vapor was set up and solved under the assumption that only the atomic component of the vapor phase reacts with the crystal surface. In calculating the ADC equilibrium on... 

Defines reaction pathways and proposes a kinetic model... 

Here, we propose a kinetic model of the relationship between a and Nt/N0 in Figure 35.9. Assuming that only the mES cell with high activity is capable of cell proliferation and divides into two daughter cells once in 25 h and that the mES cell with a low activity, on the other hand, is going to die without cell division, the increasing ratio of cellular population from 0 to 25 h is given as follows ... 

Termonia has proposed a kinetic model for fiber strength [25-27]. His calculations suggest that molecular mass, its distribution, and intermolecular forces control fiber strength. Allen s work linked the failure mode of these fibers with their morphology very closely [16, 28 30]. He was able to show that fiber pleating is responsible for the fact that one needs to consider the asymptotic modulus (modulus close to the fiber breaking point) of these fibers rather than the initial modulus to explain mechanical properties. This interpretation confirmed a clear dependence of fiber strength on both local orientation (as measured by the asymptotic modulus) and secondary interactions (as measured by shear properties). 

The preheater models are based on plug-flow behavior of both gas and the slurry phases, as the L/D ratios in preheater are usually large. Reliable estimates of the fluid properties such as viscosity and density, pressure drop across the preheater and heat transfer coefficient are needed for an optimum design of the preheater and, these have been recently reviewed by Shah (11). Parulekar et al. (17) have proposed a kinetic model for the preheater based on certain fast reactions taking place in the preheater whereas Nunez et al. (18) evaluated the hydrogen mass balance and a heat balance on the preheater. 

Terui (1972) also proposed a kinetic model for enzyme formation in the nongrowing phase... 

We propose a kinetic model which explains the nonexponential behavior as well as all the previous observations in terms of bidirectional excited state dissociation-geminate recombination mechanism (Eq. 2). However for each cycle of dissociation-recombination there is a finite chance for some ions to escape neutralization (Eq. 1). As time passes, more ions escape to the bulk and the dissociation of the R 0H becomes almost complete. The dynamic behaviour is described by time dependent equilibrium kinetics in the form of Eq. 2. 

More complex kinetic models, which relax the hypothesis of equilibrated ammonia adsorption and the participation of a single reactive site. Dumesic and co-workers proposed (104), on the basis of the reaction mechanism reported in the section 7.1, proposed a kinetic model, which is based on the following three steps ... 

The temperature depaidence of fdiotoisomerization in polymer solids yields detailed information about the effects of free volume distribution and molecular motion on the reaction process. The present authors measured the rate of trans -+ cis photoisomerization of azobenzene in a polycarbonate film over a very wide range of temperatures (4 K-423 K), and proposed a kinetic model, which consists of chemically... 

In order to explain the optical activity of living matter, Frank [19] has proposed a kinetic model which describes the accumulation of one enantiomer due to spontaneous symmetry breaking and autocatalytic enhancement of its concentration. Although the energy difference between D- and L-enantiomers is extremely small, Frank s model has been extended in order to discuss whether a very small systematic chiral perturbation rather than an accidental event can determine which enantiomer is formed [20]-[23]. For example, Kondepudi and Nelson [23] considered the reaction scheme... 

More than sixty years ago. Rose [2] proposed a kinetic model to describe the simultaneous effects of the mixing and segregation. This was based on the supposition that the rate of segregation is proportional with a segregation potential O as... 

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